Method and means for forming concrete pavements, etc.



Aug. 27, 1929. GREGG 1,726,222

OR FORMING CONCRETE PAVEMENTS, ETC

METHOD AND MEANS F Filed May 2'7. 1927 A TTORNEYI Patented Aug. 27, 1929.

UNITED STATES PATENT OFFICE.

ROBERT D. GREGG, OF KANKAKEE, ILLINOIS, ASSIGNOR OF ONE-HALE 'IO FRANK L. SHIDLER, OF KANKAKEE, ILLINOIS.

METHOD AND MEANS FOR FORMING CONCRETE PAVEMENTS, ETC.

Application filed May 27, 1927. Serial No. 194,584.

This invention relates to a method and means for forming concrete pavements, walks and like concrete work, and has for its object:

To provide a simple and effect1ve method and means for laying sectional concrete pavements, roadways, and the like, whereby the sections or slabs thereof are effectively interlocked and held from independent vertical shift in relation one to the other, after completion and during actual use, all as will hereinafter more fully appear.

In the accompanying drawing:

Fig. 1, is a perspective viewof a portion of a sectional concrete roadway formed 1n accordance with the present invention.

Fig. 2, is a detail cross section of a precast combined curb and gutter section of a roadway, illustrating the present means for molding the same.

Fig. 3, is a detail elevation of said curb and gutter section. I

Fig. 4, is an end elevation .of a straight roadway curb formed in accordance with the present invention.

Fig. 5, is a detail elevation of the same, showing an interposed nonadhesive coating between adjacent sections of the straight curbing.

' Fig. 6, is an enlarged detail section, 'illustrating an interposed compressible expansion strip between adjoining sections or slabs of the sectional concrete roadway or' the like.

Fig. 7, is a transverse section of the preferred form of the invention as applied to a sectional concrete roadway,

Fig. 8, is detail transverse section of one of the roadway sections or slabs, illustrating the present construction provided with the central longitudinal hinge provision, and showing in dotted lines companion sections or slabs constituting a narrow roadway, the last motioned slabs formed for interlocking attachment of subsequent sections or slabs, when a widening of the roadway is required.

Like reference numerals indicate like parts in the several views.

The present improvement is mainly applicable to concrete roadways and like concrete structures of the sectional type, and comprises a method and means for forming an interengaging connection between the sections or slabs of the sectional concrete structure, the method involving the formation and normal hardening or solidification, in place, of a first or initial concrete'section or slab, before an adjoining and succeeding section or slab is formed in place and in abutting relation to said first or initial unit or slab.

To such end the invention in the main, involves the formation in the abutting side or sides of the each succeeding section or slab, of pluralities of recesses and complementary projections to provide interlocking connections between the sections or slabs in their serial formation under the present method.

In the practical carrying on of the invention, a mold board 1, provided with a plurality of longitudinally spaced and centrally arranged nodes or projections 2, preferably of a hemispherical form, is employed to serve as a mold wall for the vertical abutment face of the concrete unit or slab 3 which is being molded in place. In the event that said unit or slab 3 is to have associate relation with both lateral and longitudinal sections or slabs which are subsequently formed under the present method, mold boards of a counterpart construction to the mold board 1 above described, will be employed as mold walls for the other abutting faces of the initial section or slab l, as well as that of the abutting faces of the succeeding slabs or sections.

With the above described initial concrete section or slab 3, molded in place, andafter a lapse of the usual period of time in which to set or harden, the mold board 1 is removed and a new mold cavity formed by the use of three mold boards, properly placed, and with one or more of such mold boards having a similar construction to that of the mold board 1 above described, with the vertical abutting face of the initial concrete section or slab 3 constituting the remaining wall of said mold cavity. .With the described erection of the said mold cavity, the same is then filled with a mass of concrete material, and after the same has set or hardened, the series of mold boards are removed and again set up to provide a succeeding mold cavity adapted for the formation of a succeeding concrete section or slab of a roadway or the like.

In the formation of said succeeding concrete sections or slabs 4 and 5, the concrete mass of the same is adapted to enter the plurality of recesses 6, of the initial concrete section or slab 8, in the form of a plurality of nodes or projections 7 to provide an interlocking connection between the vertical abutting face of the section or slab 3, and that of a section or slab adjoining said section or slab 3, with such connection acting to resist any independent vertical or longitudinal shift between the two sections or slabs in relation one to the other.

In that the scope of the invention involves the making of the initial concrete section or slab 3 in a suitable mold and its subsequent placing as a portion of the curb or curb and gutter of a roadway, the convenient handling of the same in placing such section or slab in proper place and position in the bed of the roadway will be aided by the formation of a recess 8 in the remote vertical face of said section or slab, with said recess of a similar {form and having aligned relation with the central one of the recesses 6 in the forward vertical face of the section or slab. lVith such construction the ordinary cross tongs generally used in handling'ice and other articles is adapted for effective engagement in the aforesaid recesses 6 and 8 in effecting the described placing and positioning of the section or slab 8.

With the above described method of mold ing the sections or slabs of a roadway or the like, it has been found in actual practical use, that the shrinkage of the concrete mass when the succeeding section or slab is molded in place, is sufficient to form the required open joint between sections or slabs. When a more flexible joint or connection is deemed necessary, the abutting vertical face of the hardened section or slab will be painted with a coating 9 of asphalt cement previous to the molding of a succeeding section or slab, see Fig. 5.

When still greater flexibility is required at such joints, the above described coating 9 of cement will be replaced by a compressible expansion strip 10, interposed between the slabs during the molding of'the same under the present method, or subsequent to their formation and setting.

In the application of the invention to roadway, the central longitudinal sections or slabs forming the middlecor crown of the roadway and formed in accordance with the present method, may be made in halves separated by a longitudinal parting strip 11, constituting the usual hinge connection at the crown of the roadway.

Having thus fully described my invention, what I claim and desire to secure by Letters Patent, is

1. The herein described method of forming concrete roadways and the like, the same comprising molding an initial concrete slab with a plurality of recesses of a hemispherical form in one of its abutting faces, allowing time for such slab to harden, then molding a succeeding slab against the abutting face -of the initial slab, with the material of the succeeding slab entering the recesses in the initial slab to form an interlocking connection.

2. The herein described method of molding concrete roadway, the same comprising the initial molding of a curb slab in place and with a plurality of hemispherical recesses in one of its vertical faces, allowing time for said slab to harden, then molding a succeeding roadway slab against the abutting face of the curb forming slab, with the material of the succeeding slab entering the recesses of the curb forming slab to form an interlocking connection, the initial slab having a complementary hemispherical recess in its remote face in aligned relation to the central one of the recesses in the forward face of said slab to provide means for corn venient handling of same.

3. The herein described method of molding concrete roadways, the same comprising the initial molding of a curb slab in place and with a plurality of recesses of a hemispherical form in one of its abutting faces, allowing for such slab to harden, then molding a succeeding roadway slab against the abutting face of the curb forming slab, with the material of the succeeding slab the recesses of the curb forming slab to form an interlocking connection.

Signed at Chicago, Illinois, this 30th day of April, 1927.

ROBERT D. GREGG. 

